The present invention relates to an occupant protective apparatus and, in particular, to an occupant protective apparatus which is capable of reducing deceleration to be applied to an occupant when a vehicle collision occurs.
Recently, in order to enhance the effect of occupant protection in a collision, there have been proposed various vehicle body structures in which a deforming mode of the other remaining portions of a vehicle body than the passenger room portion of the vehicle body in a collision is set properly to thereby be able not only to reduce the deceleration of the passenger room portion of the vehicle body but also to prevent the deformation of the other remaining portions of the vehicle body from extending over to the passenger room portion of the vehicle body (see Japanese Patent Unexamined Publication No. Hei. 7-101354).
On the other hand, the deceleration of the occupant constrained to a seat by a seat belt can firstly start at the time when a forward going inertial force acting on the occupant in the collision is received by the seat belt. Here, since the spring action of the seat belt cannot be removed, the inertial force causes the occupant to move forward and the deceleration of the occupant reaches its peak value at the time when the extension of the seat belt reaches its limit. It is generally said that the peak value of the occupant deceleration increases as the moving amount of the occupant due to the inertial force increases and, normally, the peak value of the occupant deceleration becomes higher than the average deceleration of the passenger room portion of the vehicle body. Therefore, in order to reduce an impact to be given against the occupant due to the collision, the deceleration of the vehicle body must be adjusted in such a manner that a delay in the starting time of the occupant deceleration with respect to the vehicle body deceleration can be minimized.
However, it is substantially impossible to connect the occupant to the vehicle body as an integral unit and, especially, in the case of a compact vehicle in which it is difficult to secure a sufficient stroke in the other remaining portions of the vehicle body than the passenger room portion thereof, it is difficult to reduce the occupant deceleration further simply using a conventional occupant protecting method in which the deceleration of the passenger room portion in a collision is reduced by setting the deforming mode of the vehicle body properly.
The present invention aims at eliminating the drawbacks found in the above-mentioned conventional occupant protective apparatus. Accordingly, it is an object of the invention to provide an occupant protective apparatus which can reduce not only the size of the vehicle body but also the deceleration of the occupant at a further improved manner.
In attaining the above object, according to the invention, there is provided an occupant protective apparatus which comprises: one or more seats (1) respectively supported on a vehicle body so as to be movable along the direction of a force acting on the vehicle body in the case of a collision, and each including a seat belt (3) for constraining an occupant (2) seated on the seat (1); an inertia mass member (in the illustrated embodiment, a battery 5) supported on the vehicle body in such a manner that, when the vehicle body stops suddenly in the collision, it continues to move in the advancing direction of a vehicle in which the vehicle has been advancing until the time just before the collision occurs; and, a mutually reversing mechanism (in the illustrated embodiment, two parallel links 6) for connecting together the seat and inertia mass member in such a manner that they can move the seat in the opposite direction to the moving direction of the inertia mass member in the collision.
According to the present occupant protective apparatus, for example, as soon as a forward running vehicle collides head on with a structure on the road, a backward going acceleration is applied to the seat, so that higher deceleration than the deceleration of the vehicle body is generated in the seat. Therefore, the constraining force of the seat belt for constraining the forward movement of the occupant can be enhanced.
Especially, the present occupant protective apparatus may further include force generating mechanism (in the illustrated embodiment, a stopper 7) for applying a forward going force to the seat after the above-mentioned backward going acceleration is applied. That is, after occurrence of the collision, in case where a forward going force is applied to the seat with a proper time delay with respect to the backward going acceleration, a forward going inertial force acting on the occupant in the collision can be made constant instantaneously, so that the deceleration of the vehicle body and the deceleration of the seat and occupant can be made equal to each other in the early stage of the collision.